This is a proposal to develop a microspectrofluorimetric facility equipped with a picosecond pulsed laser source, image intensification, digital image processing and time-correlated single-photon counting capabilities. This facility will serve as 1) a shared resource for a group of investigators whose research is supported by the NIGMS, 2) an available resource to a limited number of other qualified scientists, and 3) as a unique instrumentation system with which to explore the application of laser technology to biomedical research. Some of the immediate applications of this facility will include: a) time-domain spectroscopy at the single cell level. b) cell surface topography studies with single intact live cells and c) fast kinetic studies of biochemical processes either in single cells or in purified biochemical preparations.